Charon, known as (134340) Pluto I, is the largest of the five known natural satellites of the dwarf planet Pluto. It has a mean radius of 606 km (377 mi). Charon is the sixth-largest known trans-Neptunian object after Pluto, Eris, Haumea, Makemake, and Gonggong. It was discovered in 1978 at the United States Naval Observatory in Washington, D.C., using photographic plates taken at the United States Naval Observatory Flagstaff Station (NOFS).
Valles Marineris is a system of canyons that runs along the Martian surface east of the Tharsis region. At more than 4,000 km (2,500 mi) long, 200 km (120 mi) wide and up to 7 km (23,000 ft) deep, Valles Marineris is the largest canyon in the Solar System.
A rift valley is a linear shaped lowland between several highlands or mountain ranges produced by the action of a geologic rift. Rifts are formed as a result of the pulling apart of the lithosphere due to extensional tectonics. The linear depression may subsequently be further deepened by the forces of erosion. More generally the valley is likely to be filled with sedimentary deposits derived from the rift flanks and the surrounding areas. In many cases rift lakes are formed. One of the best known examples of this process is the East African Rift. On Earth, rifts can occur at all elevations, from the sea floor to plateaus and mountain ranges in continental crust or in oceanic crust. They are often associated with a number of adjoining subsidiary or co-extensive valleys, which are typically considered part of the principal rift valley geologically.
Odysseus is the largest crater on Saturn's moon Tethys. It is 445 km across, more than 2/5 of the moon's diameter, and is one of the largest craters in the Solar System. It is situated in the western part of the leading hemisphere of the moon—the latitude and longitude of its center are 32.8°N and 128.9°W, respectively. It is named after the Greek hero Odysseus from Homer's the Iliad and the Odyssey.
A cryovolcano is a type of volcano that erupts gases and volatile material such as liquid water, ammonia, and hydrocarbons. The erupted material is collectively referred to as cryolava; it originates from a reservoir of subsurface cryomagma. Cryovolcanic eruptions can take many forms, such as fissure and curtain eruptions, effusive cryolava flows, and large-scale resurfacing, and can vary greatly in output volumes. Immediately after an eruption, cryolava quickly freezes, constructing geological features and altering the surface.
Hydra is a natural satellite of Pluto, with a diameter of approximately 51 km (32 mi) across its longest dimension. It is the second-largest moon of Pluto, being slightly larger than Nix. Hydra was discovered along with Nix by astronomers using the Hubble Space Telescope on 15 May 2005, and was named after the Hydra, the nine-headed underworld serpent in Greek mythology. By distance, Hydra is the fifth and outermost moon of Pluto, orbiting beyond Pluto's fourth moon Kerberos.
The dwarf planet Pluto has five natural satellites. In order of distance from Pluto, they are Charon, Styx, Nix, Kerberos, and Hydra. Charon, the largest, is mutually tidally locked with Pluto, and is massive enough that Pluto and Charon are sometimes considered a binary dwarf planet.
Coprates Chasma is a huge canyon in the Coprates quadrangle of Mars, located at 13.4° south latitude and 61.4° west longitude, part of the Valles Marineris canyon system. It is 966 km (600 mi) long and was named after a classical albedo feature name. It was named from the classical Greek name for the Dez River in Persia.
Danube Planum is a rifted mesa on the surface of Jupiter's moon Io. It is located on Io's trailing hemisphere at 22.73°S 257.44°W. Danube Planum is 244.22 kilometers across and 5.5 km tall. The mountain is bisected by a 15-to-25-kilometer-wide, northeast–southwest-trending canyon, splitting the mountain into two main east and west mountains, with several additional blocks at the southern end of the fracture. The outer margin of the plateau is marked by 2.6-to-3.4-km-tall scarps. Mass wasting in the form of landslide deposits are visible along the base of the western half of Danube Planum. Two volcanic depressions, known as paterae, lie at northern and southern ends of mountain. The volcano at the northern end, Pele, is one of the most active volcanoes on Io. One of the faults that helped form Danube Planum may also act as a conduit for magma to rise to the surface at Pele.
The geology of Charon encompasses the characteristics of the surface, crust, and interior of Pluto's moon Charon. Like the geology of Pluto, almost nothing was known of Charon's geology until the New Horizons of the Pluto system on 14 July 2015. Charon's diameter is 1,208 km (751 mi)—just over half that of Pluto. Charon is sufficiently massive to have collapsed into a spheroid under its own gravity.
Challenger Colles is a range of hills on Pluto near the eastern edge of Sputnik Planitia. Discovered by the New Horizons team in July 2015, It is named in honor of the Space Shuttle Challenger, which was destroyed with all seven crew lost on January 28, 1986. The name Challenger Colles was officially approved by the International Astronomical Union on May 27, 2022.
Vulcan Planum, or Vulcan Planitia, is the unofficial name given to a large plain on the southern hemisphere of Pluto's moon Charon. It discovered by New Horizons during its flyby of Pluto in July 2015. It is named after the fictional planet Vulcan in the science-fiction series Star Trek. The name is not approved by International Astronomical Union as of 2020.
The Coleta de Dados Colles are a cluster of hills ("colles") on the smooth plains of Sputnik Planitia on Pluto. The hills are over 100 km from the major mountain ranges to the west, and appear to be blocks of water ice floating in the denser nitrogen ice of Sputnik Planitia. The hills were informally named on July 28, 2015, by the research team of the New Horizons mission after the first Brazilian satellite, the Satélite de Coleta de Dados. The ridge's name has yet to be recognized officially by the IAU.
Wright Mons is a large, roughly circular mountain and likely cryovolcano on the dwarf planet Pluto. Discovered by the New Horizons spacecraft in 2015, it is located southwest of Sputnik Planitia within Hyecho Palus, adjacent to the Tenzing Montes and Belton Regio. A relatively young geological feature, Wright Mons has attracted attention as one of the most apparent examples of recent geological activity on Pluto and borders numerous other similarly young features. Numerous semi-regular hills surround and partially construct the flanks of Wright Mons. Their nature remains unexplained, with few, if any, direct analogs elsewhere in the Solar System.
Oz Terra is the unofficial name given to a major geological region on Charon. The Pluto-facing hemisphere of Charon is divided onto two primary regions; Oz Terra in the north and Vulcan Planum in the south. These regions are separated by a series of scarps near Charon's equator, particularly Serenity Chasma and Mandjet Chasma. The region was discovered by New Horizons during its flyby of Pluto in July 2015.
Mandjet Chasma is a chasma on Pluto's moon, Charon. Mandjet Chasma is 385 km (239 mi) long, and about 5–7 km (3.1–4.3 mi) deep with an average width of 30 km (19 mi). The chasma is part of a global tectonic belt: a series of canyons, scarps, and troughs that traverse the face of Charon along the northern edge of Vulcan Planum. The feature was discovered using stereoscopic processing of New Horizons images.
The climate of Pluto concerns the atmospheric dynamics, weather, and long-term trends on the dwarf planet Pluto. Five climate zones are assigned on the dwarf planet: tropics, arctic, tropical arctic, diurnal, and polar. These climate zones are delineated based on astronomically defined boundaries or sub-solar latitudes, which are not associated with the atmospheric circulations on the dwarf planet. Charon, the largest moon of Pluto, is tidally locked with it, and thus has the same climate zone structure as Pluto itself.
Caleuche Chasma is a Y-shaped chasma on Pluto's moon, Charon. Caleuche Chasma is 400 km (250 mi) long. The feature was discovered using stereoscopic processing of New Horizons images. At approximately 13 km (8.1 mi) deep, it is the deepest known feature on the natural satellite, and one of the deepest known canyons in the Solar System.
Leviathan Patera is a major cryovolcanic caldera on Neptune's largest moon Triton. Discovered by the Voyager 2 spacecraft in 1989, Leviathan Patera is located in Monad Regio and within Cipango Planum's western regions. Leviathan Patera is approximately 80 kilometers in diameter and may be the center of one of the largest cryovolcanic or volcanic edifices in the Solar System.
Tuonela Planitia is an elongated plain and probable cryolava lake on Neptune's moon Triton. Located in Triton's northern hemisphere within Monad Regio, it overlies part of Triton's unusual cantaloupe terrain. As with neighboring Ruach Planitia and other walled plains on Triton, Tuonela Planitia is among the youngest features on Triton's surface.
